Pneumatic percussion tool



Oct. 31, 1939. c. 1.. TOWLE PNEUMATIC PERCUSSION TOOL Filed D66' 2, 1937 INVEN TOR.- Charlas L. To

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ATTORNEYS.

WI TNESSES (Mam Patented Oct. 31, 1939 UNI-TE STA gran 8 Glaims.

This invention relates to percussion tools, one of its purposes being to provide in one unit an independently powered or self-powered tool that can be made compact and light enough for portability, and for convenient operation by a workman. Another object of the invention is to combine the advantages of an internal combustion engine as the ultimate source of power with the flexibility of action and other well-known char- 10 acteristics of pneumatic actuation. A further advantage is that of being able to fabricate the tool, if desired, mainly by combining mechanisms and parts already commercially available, with a minimum of alterations and of special parts and accessories. This allows of a relatively low cost of manufacture, even in producing the tools on a relatively small scale, Still other features and advantages of the invention will appear from the following description of one species or form of 2 embodiment, and from the drawing. All the features and combinations shown and described are, indeed, of the invention, so far as novel over the prior art.

The invention is particularly applicable to tamping tools, adapted, amongst other uses, for tamping railroad ties, and it is here illustrated and explained in a form of embodiment. well suited for this purpose.

The drawing shows a vertical axial section through a tool conveniently embodying the invention.

The tool here illustrated comprises as its principal components a gas-engine mechanism Ill similar to that of an outboard motor for small boat propulsion, and a pneumatic mechanism and tool ll like those of a well-known pneumatic tamper. The particular engine It shown is that of an Evinrude four-cylinder, two-cycle motor, and the pneumatic mechanism and tool I l are those of an Ingersoll MT-l, MT-2, or NIT-3 tie tamper. As these are commercially wellknown devices, no complete description thereof 7 l2, l2 and l3, is base. central bore wherein is mounteda hollow structure 28, securely attached to the block, which serves as a frame for mounting other parts, and also in a manner as a crankcase containing the crank-shaft I l. The lower shaft bearing 2! is mounted in the hollow structure Zilrand the upper shaft bearing 22 and an intermediate bearing and carburetor structure 23 may (or may not) form part of the structure 20, or be mounted therein. Other parts that may 10 be mounted in the structure 29 include fuel supply and water circulating pumps 24 and 25, whose respective suction and delivery connections 26, 21 are also shown. These parts are shown just as when the engine 8! is used for its original pur- 15 pose. Around the lower portion of the structure 2e there is shown a housing and reservoir structure Sill, including fuel and compressed air compartments Si, 32, which may be attached to the structure 28 or to the cylinder block l8, or 20 both. The engine and compressor cylinders l2, l2 and l3, it? are cooled by the original water jacket and cooling arrangements, just as if they were still operated as a four-cylinder gasoline engine. Other original engine accessories that are retained 25 include the fly-wheel magneto 33 with connections 34 to spark plugs 35 in cylinders l2, l2, and the exhaust piping S6 to mufiler 37. An upper sheet metal housing lil, shown as bolted to the structure 30 at M, coacts with this structure 30 30 to enclosure most or all of the parts already mentioned (excepting the muffler 31), but is readily removable for access to any of the parts. Handles d2, 42 for manipulating the tamper may be attached to the housing Ml. 35

Air to be compressed may be taken inindependently for the two cylinders I3, l3, bymeans of intakes 43, 43 that open through the casing walls 49 and are connected to the suction checkvalves M, M, interposed in these intakes 43, 63. From the cylinders l3, it, the compressed air is delivered through discharge check-valves 46, 46 and pipes 41, 41 to the reservoir compartment or tank 32, which serves to equalize the air pressure and flow, and also'aliords radiating surface to cool the air somewhat after compression. An additional check-valve i'la is shown in the pipe 41 adjacent the reservoir 32, to preclude back flow ofair to the cylinders l3, 3. The air reservoir 50 tank 32 may be equipped with a safety valve 48, to, prevent excessive pressure from building up in this tank under any circumstances.

To the lower end of the frame structure 28 is attached (as by bolts 49) the upright cylinder and As shown, air filters 35, 4-5 are guide or tool holder structure 50 of the pneumatic mechanism H, which is coaxial with the shaft M and the structure 20. From the tank 32, air under pressure is supplied to this pneumatic mechanism l I through a pipe The lower portion of the structure 50 affords a guide and holder for the (hexagonal) shank 53 of the tamping tool 54, whose upper end is struck by the pneumatic piston 55 on its downstrokes. As here shown, the tool-guiding and holding means include a tool retainer sleeve 56, internally flanged at its lower end, which is removably fitted on a reduced extension 51 of the pneumatic cylinder or barrel liil, and is detachably secured thereto by bolts 58 as usual. The tool shank 53 has the external enlargement or flange 68 for coact ing with the superjacent retaining washer (or fixed nozzle) El-that engages under the internal flange or shoulder 62 of the barrel extension 5land also for coacting with the subjacent two-part sleeve (or loose nozzle) 63, which engages under the lower end of the part 51 and abuts against the split elastic (rubber) bufier collar M, above the split steel washer G5 in the lower end of the retainer.

Besides the features already described, which correspond essentially to those of the aforementioned Ingersoll tie tampers, the pneumatic mechanism here shown includes provisions for varying its action between a light, fast blow and a slow heavy blow, by adjustment that can easily be made without taking the mechanism apart. For this purpose, the extension part 51 is shown as a sleeve separate from the main cylinder or barrel part 50, and fiting adjustably on a reduced lower portion 66 of said part 50. Any suitable means may be provided for adjusting the part 51 up and down on the barrel portion 66, such as (hexagonal headed) screws 61 threaded through ears or lugs 68 on the barrel 50 and having their reduced lower ends engaged and free to turn in ears or lugs 69 on the part 51. As shown, the ears 69 are snugly engaged between shoulders on the screws 51 and separate heads ll suitably secured to the lower extremities of the screws. Locknuts l2 are shown on the screws 61, for locking the part 51 in any desired up and down position relative to the barrel 50. Through the wall of the part 51 extends an exhaust port 14, which opens into an exhaust slot '55 in the wall of the barrel portion 66. This slot 15 is of such length that the port 14 opens into it in all up and down positions of the part 51.

By adjusting the part 51 up and down, the tool shank 53 is also adjusted up and down relative to the main barrel or cylinder 59, so that the piston 55 shall hit the tool and rebound after traveling downward a greater or less distance in the cylinder. At the extreme upper adjustment, this results in a rapid succession of relatively light blows, and at the extreme lower adjustment in a slower succession of heavier blows, with blows of intermediate force and rapidity at intermediate adjustments.

Having thus described my invention, I claim:

1. A self-powered percussion tool comprising in one portable unit an internal combustion engine and a compressor, an upright crank shaft driven by the engine and driving the compressor, and an upright downward-acting pneumatic percussion mechanism beneath the said engine and compressor, attached to them at one end and loaded with their weight to hold its tool against the work, and supplied with motive fluid from said compressor.

2. A self-powered percussion tool comprising in one'portable unit an internal combustion engine and a compressor, an upright crank shaft driven by the engine and driving the compressor,

an upright downward-acting pneumatic percussion mechanism beneath the said engine and compressor, attached to them at one end and loaded with their weight to hold its tool against the work, and supplied with motive fluid from said compressor, and a housing around said engine and compressor, attached to them and carrying handles at its periphery for manipulating the tool in use.

3. A self-powered percussion tool comprising in one portable unit an internal combustion engine and a compressor, with a common crankshaft driven by the engine and driving the compressor, a common cooling system and a frame structure for said engine and compressor, a fuel pump for said engine and a cooling fluid circulating pump for said system, both driven by the aforesaid crank-shaft, a reservoir structure around said crank-shaft, including fuel and compressed fiuid compartments or reservoirs supplying said engine and supplied by said compressor, respectively, and a pneumatic percussion mechanism attached to said frame structure and supplied with motive fluid from said compressed fluid reservoir.

4. A self-powered percussion tool comprising in one portable unit a horizontally arranged internal combustion engine, a horizontally arranged compressor attached to said engine, an upright crank shaft driven by said engine and driving said compressor,and an uprightverticallyacting pneumatic percussion mechanism attached to said engine and compressor substantially in line with their said crank shaft, and supplied with motive fluid from said compressor.

5. A self-powered percussion tool comprising in one portable unit an internal combustion engine and a compressor, including engine and compressor cylinders, with an upright crankshaft driven by the engine and driving the compressor, a central hollow frame structure where to the engine and compressor cylinders are attached, and in which said crank-shaft is mounted, and a pneumatic percussion mechanism comprising an upright cylinder and tool holder structure attached at its end to the end of said frame structure, and supplied with motive fluid from said compressor.

6. A self-powered percussion tool comprising in one portable unit an internal combustion engine and a compressor, including a cylinder block with horizontal engine and compressor cylinders therein; a hollow frame structure attached to said cylinder block; an upright crankshaft mounted in said hollow frame structure, driven by said engine and driving said compressor; a reservoir structure mounted around said hollow frame structure adjacent said cylinder block, and including fuel and compressed air compartments supplying said engine and supplied by said compressor, respectively; a pneumatic percussion mechanism supplied with motove fluid from said compressed air compartment and comprising an upright cylinder and tool holder structure attached at one end to the end of said frame structure; and a housing around said cylinder block coacting with said reservoir structure to enclose the engine and compressor.

'7. A self-powered percussion tool comprising in one portable unit an internal combustion engine and a compressor, an upright crank shaft driven by the engine and driving the compressor, an upright vertically-acting pneumatic percussion mechanism supplied with motive fluid from said compressor and comprising a. barrel or cy1- inder attached at its end to said engine and compressor, substantially in line with their said crank shaft, and a tool holder carried by said barrel adjustable lengthwise thereof, to vary the action of the percussion mechanism on the tool.

8. A self-powered percussion tool comprising in one portable unit an internal combustion engine and a compressor, an upright crank shaft driven by the engine and driving the compressor,

an upright vertically-acting pneumatic percussion mechanism supplied with motive fluid from said compressor and comprising a barrel or cylinder attached at its end to said engine and compressor, substantially in line with their said crank 5 having an exhaust port through its wall, communicating with said exhaust opening in all po- 10 sitons of adjustment of said tool-holder.

CHARLES L. TOWLE. 

